Check Engine Light
Hello all, Registered today to get help with what mechanics can't find. My name is dan and I have a 91 Ranger super cab 4.0l. The ck engine light has been coming on. Mechanic #1 said o2 sensor, he replaced. light off about 4 days and back on. I took it back, he said faulty 02 sensor, replaced for free. 4 days on again. went to mechanic #2. bad 02 sensor, told him just replaced twice. he said other things show that code, he would just have to start replacing things. can't afford guess work. I replaced PVC valve Light out 2 days. Replaced all vac lines I could and checked one I couldn't. I have no egr valve. I have had thi truck for ten years and have only had to replace belt and fuel pump. It starts and runs fine, I go about 5.6 miles and the light comes on. if I turn it off and restart, the light doesn't come back on for several miles.
Anyone have any ideas.